IWebPartRow.GetRowData Method (RowCallback)
Returns the data for the row that is being used by the interface as the basis of a connection between two WebPart controls.
Assembly: System.Web (in System.Web.dll)
Parameters
- callback
-
Type:
System.Web.UI.WebControls.WebParts.RowCallback
A RowCallback delegate that contains the address of a method that receives the data.
Use this method to retrieve the data row values passed by the interface. The provider implements this method, and the consumer invokes it at the point when the consumer is ready to process or render data.
The following code example shows the implementation and use of the GetRowData method. The complete example is shown in the class overview for the IWebPartRow interface. The provider control implements the GetRowData method, returning the value of a particular row in the data table. The consumer control calls the GetRowData method in its OnPreRender method, so that the value of the data can be written to the page.
Imports System Imports System.Collections Imports System.ComponentModel Imports System.Data Imports System.Reflection Imports System.Security.Permissions Imports System.Web Imports System.Web.UI Imports System.Web.UI.WebControls Imports System.Web.UI.WebControls.WebParts Namespace Samples.AspNet.VB.Controls ' This sample code creates a Web Parts control that acts as a provider ' of row data. <AspNetHostingPermission(SecurityAction.Demand, _ Level:=AspNetHostingPermissionLevel.Minimal)> _ <AspNetHostingPermission(SecurityAction.InheritanceDemand, _ Level:=AspNetHostingPermissionLevel.Minimal)> _ Public NotInheritable Class RowProviderWebPart Inherits WebPart Implements IWebPartRow Private _table As DataTable Public Sub New() _table = New DataTable() Dim col As New DataColumn() col.DataType = GetType(String) col.ColumnName = "Name" _table.Columns.Add(col) col = New DataColumn() col.DataType = GetType(String) col.ColumnName = "Address" _table.Columns.Add(col) col = New DataColumn() col.DataType = GetType(Integer) col.ColumnName = "ZIP Code" _table.Columns.Add(col) Dim row As DataRow = _table.NewRow() row("Name") = "John Q. Public" row("Address") = "123 Main Street" row("ZIP Code") = 98000 _table.Rows.Add(row) End Sub 'NewNew <ConnectionProvider("Row")> _ Public Function GetConnectionInterface() As IWebPartRow Return New RowProviderWebPart() End Function 'GetConnectionInterface Public ReadOnly Property Schema() As _ ComponentModel.PropertyDescriptorCollection Implements IWebPartRow.Schema Get Return TypeDescriptor.GetProperties(_table.DefaultView(0)) End Get End Property Public Sub GetRowData(ByVal callback As RowCallback) _ Implements IWebPartRow.GetRowData callback(_table.Rows) End Sub End Class 'RowProviderWebPart ' This sample code creates a Web Parts control that acts as a consumer ' of row data. <AspNetHostingPermission(SecurityAction.Demand, _ Level:=AspNetHostingPermissionLevel.Minimal)> _ <AspNetHostingPermission(SecurityAction.InheritanceDemand, _ Level:=AspNetHostingPermissionLevel.Minimal)> _ Public NotInheritable Class RowConsumerWebPart Inherits WebPart Private _provider As IWebPartRow Private _tableData As ICollection Private Sub GetRowData(ByVal rowData As Object) _tableData = CType(rowData, ICollection) End Sub Protected Overrides Sub OnPreRender(ByVal e As EventArgs) If Not (_provider Is Nothing) Then _provider.GetRowData(New RowCallback(AddressOf GetRowData)) End If End Sub Protected Overrides Sub RenderContents(ByVal writer As HtmlTextWriter) If Not (_provider Is Nothing) Then Dim props As PropertyDescriptorCollection = _provider.Schema Dim count As Integer = 0 If Not (props Is Nothing) AndAlso props.Count > 0 _ AndAlso Not (_tableData Is Nothing) Then Dim prop As PropertyDescriptor For Each prop In props Dim o As DataRow For Each o In _tableData writer.Write(prop.DisplayName & ": " & o(count)) writer.WriteBreak() writer.WriteLine() count = count + 1 Next o Next prop Else writer.Write("No data") End If Else writer.Write("Not connected") End If End Sub <ConnectionConsumer("Row")> _ Public Sub SetConnectionInterface(ByVal provider As IWebPartRow) _provider = provider End Sub End Class 'RowConsumerWebPart End Namespace ' Samples.AspNet.VB.Controls
Available since 2.0